The features of power devices using gallium oxide are that they can operate in harsh environments such as high temperature and high radiation, that there is little loss of power in the process of manipulating electricity, and that the manufacturing cost can be lower than that of rival new materials. It is expected to be applied in fields such as power transmission systems, trains, and electric vehicles where equipment voltage is high. If the new device can be used without loss of power, which is essential in all fields, it will save energy and contribute to environmental issues. As for applications other than power devices, there are possibilities for applications in 4K and 8K high-sensitivity image sensors, ultraviolet sensors, and scintillators for medical equipment.